At least 149 people died when a powerful earthquake of magnitude 7.1 struck central Mexico on Tuesday, toppling buildings in the heavily populated capital where rescuers scoured frantically under the rubble of ruins for survivors.

First responders work on removing the rubble of a collapsed building looking for survivors trapped underneath, after a 7.1 earthquake in Mexico City.(AP Photo)

Casandra Hidalgo ran outside when the earthquake struck just in time to see the seven-story apartment building opposite the café where she works tumble into a heap.

“It fell to the ground in front of our eyes, people were running everywhere around it, but we’ve been standing here since and no one has come out of the building,” Hidalgo, 18, told the Guardian as she stood in front of the enormous pile of dusty rubble in the Mexico City’s leafy La Condesa neighbourhood.

At least 149 people are dead after the 7.1 earthquake struck at about 1pm on Tuesday causing widespread destruction in Mexico City and neighbouring states – exactly 32 years since a 1985 tremor devastated the city. The epicentre of the tremor was close to the town of Raboso in the state of Puebla, 120km from the capital.

The quake devastated La Condesa, one of the city’s most prosperous neighbourhoods, flattening several buildings and leaving scores more damaged and unstable.

The collapsed apartment block on the circular boulevard Amsterdam Avenue was instantly cloaked by clouds of white dust as a strong smell of gas filled the air. The building comprises three apartments on each floor – no one knows how many people were inside when the earthquake hit.

Monica Saavdera’s 87-year-old mother was among the residents at home when the earthquake hit. “I pray that she’s already dead, that she’s not trapped underneath alive,” Saavdera said, comforting her mother’s sobbing domestic worker who survived because she had popped out to run some errands when the quake struck.

The first to arrive on the scene, minutes after the building collapsed, was a group of construction workers who had been working a couple of blocks away. Within minutes, they took control and started trying to lift the rubble by hand until neighbours arrived with shovels, saws, wheelbarrows and plastic buckets to help.

Within a couple of hours there were hundreds of people trying to assist but no authorities to take charge. Every few minutes there were shouts of “silence, silence” as the volunteers on top of the rubble struggled to listen for survivors from deep beneath the ruins.

“It’s chaos, people want to help but civil protection should be here and in charge, there are too many people on top of the debris it is dangerous for everyone” said Israel Belmonte, an education ministry worker who is also part of the health and safety brigade.

Dozens of civilians, some wearing cycle helmets and garden gloves for protection, were scattered across the metres-tall rubble heap.

Doctors and nurses who live nearby were also on the scene and had set up a makeshift medical centre even before the first ambulances arrived more than two hours later. The first firefighters took even longer to arrive.

Rescuers, firefighters, policemen, soldiers and volunteers remove rubble and debris from a flattened building in search of survivors after a powerful quake in Mexico City on September 19, 2017.
(AFP Photo)

Hundreds of people formed human chains and cleared debris by hand in order to allow the emergency services through, passing broken concrete slabs, fallen trees and sharp metal poles from person to person out of the way. Plastic crates and shopping trolleys from a nearby supermarket were used to move the heavier debris.

Several civilians needed medical treatment after being hit by debris.

One frustrated man shouted at a group of police officers. “Don’t just stand there, help, everyone has to help, why aren’t you doing anything?”

Donations of water and medicines started flooding in, but volunteers urgently called for more supplies. “We need batteries, torches, blankets, another megaphone, more tools, please bring us what we need,” one man said.

At about 5pm, as the authorities and machinery started to arrive , one of the volunteers shouted out that help was needed a few blocks away where another building had collapsed. Dozens of people started running in that direction, where truckloads of navy and army officers were also converging. There, riot police held signs with lists of medicines needed included antibiotics and painkillers.

Away from Amsterdam Avenue, there were smashed-up cars, broken windows, cracked walls and partially collapsed buildings in every direction.

Mayte Ferriero and her daughter Yeziel, 22, lived on the fifth floor of the collapsed Amsterdam Avenue building. They were out having a late breakfast when the earthquake struck, but their domestic worker was inside. “She’s in there, so is the security guard, who knows how many others,” said Ferriero